Category: energy generation

As we contemplate the future of energy, and the combination of utility-level and distributed energy, and of different types – solar PV, solar thermal (heat your own hot water for showers), wind, etc., one question I have asked myself is how much energy can realistically be produced by the solar collectors on the roofs of our houses and office buildings in the U.S.?

It turns out the United States government has done some research on this! There’s a very interesting set of Department Of Energy reports, including one (PDF) on the market opportunities for grid-tied distributed solar PV. It figures out, state by state, how much roof surface is available, how attractive the incentives and infrastructure are (e.g., is there net metering?) and uses some simple algorithms to come up with an expected market penetration for solar PV on commercial and residential roofs. The resulting amount of electricity generated in this distributed fashion is amazingly high. Their best case scenario has installed MWs of rooftop solar PVs rising from about 2,000 in 2008 to almost 25,000 in 2015, more than a factor of ten increase over seven years.

The report uses conservative numbers for solar PV cost improvements – breakthoughs and innovations like the ones mentioned in Technology Review every week (like this one), will make the market penetration even faster (and higher) as they come to market.

I was pleased to see that our government has done this kind of research. Think what could be done if funding for renewable energy research and development was an order of magnitude higher!

Moore’s Law depended (and still depends) on a constant flow of breakthrough technologies, processes, scale, and designs. You can’t necessarily predict how Moore’s Law will continue to hold two years from now, or five years from now, but you can be confident that through some combination of technologies, processes, and designs, the price/performance of IT will continue to decline at an exponential rate.

The top five green energy stories of 2008 give an indication that the same types of forces are at play in the green energy world. Numbers 1, 2, and 3 each represent a potential 10x reduction in the cost of the most expensive part of a particular energy flow. For number 4, Gore used the bully pulpit of a Nobel Prize and Oscar (and, oh yeah, he was nearly president) in a most constructive way. And number 5 illustrates that green energy technologies are on a growth rate of doubling about every 18 months.

Did these stories excite you as much as they did me? Were there other green energy stories in August that you feel are more important?

“The clean energy industry is maturing and its backers remain bullish. These findings should empower governments both North and South to reach a deep and meaningful new agreement by the crucial climate convention meeting in Copenhagen in late 2009. It is increasingly obvious to the public and investors alike that the transition to a low-carbon society is both a global imperative and an inevitability. This is attracting an enormous inflow of capital, talent and technology. But it is only inevitable if creative market mechanisms and public policy continue to evolve to liberate rather than frustrate this clean energy dawn. What is unfolding is nothing less than a fundamental transformation of the world’s energy infrastructure.”

Thanks to blow-hard winds, the United States has just become the world’s largest generator of wind energy.

Germany previously held this distinction, though since the United States has about 26 times more land than Germany, the milestone isn’t a huge surprise. Nonetheless, we weren’t expected to reach this point until late 2009. [Emphasis added – npd]

The key point is that we’re ahead of schedule on renewables, because the schedule was based on linear growth projections. The big question that remains is not whether the growth is exponential, but what’s the time period for doubling? Is it two years? Three years? One year? What do you think?

One of my pet peeves is news stories about energy that say something like “Flokistan just added 100 MWs in solar panels to its grid. This is enough to power 150 homes,” with no further numbers. I always want to know the context, like how many MWs does Flokistan use? How many homes are there in Flokistan? How does 100 MWs in solar panels compare in cost with putting in 100 MWs of coal-fired powerplants, and how long will it take to pay back?

The energy field is full of numbers – cars emit 19 tons of CO2 per year, solar panels cost $0.20/kWh, PG&E just contracted for 800 MWs of solar power in California. They are used freely, but seldom put into context. So I was very happy to discover an interesting online resource over the weekend: Richard Muller’s U.C. Berkeley class “Physics For Future Presidents.”

In one semester, my goal is to cover the physics that future world leaders need to know (and maybe present world leaders too.

Chapter one, Energy and Power (and the physics of explosions), of his textbook is online (at least temporarily) and it’s fascinating. Most interesting is the table near the beginning comparing the energy content per gram of various substances, including TNT, gasoline, hydrogen, various batteries, an asteroid traveling at 30 km/sec, and even chocolate chip cookies.

For example, a gram of gasoline has about 15 times as much energy content as a gram of TNT, and about half again as much energy content as a gram of ethanol. Hydrogen has almost three times the energy content of gasoline per gram, but even as a liquid, hydrogen is only about 1/10 as dense as gasoline, meaning that per volume, it has about 1/3 the energy content. Muller’s paper is full of useful rules of thumb, such as the following:

Remember this: Compared to gasoline, liquid hydrogen has

3 x more energy per gram (or per lb)

3 x less energy per gallon (or per liter)

He then goes on to discuss the relative merits of different forms of energy for powering cars, noting that gasoline is a particularly desirable fuel given its very high energy content and ease-of-use compared to, say hydrogen. Or batteries – which have 100x less energy density than gasoline. He also explains why having a big meteorite or asteroid hit Earth would be a bad thing.

If you’re interested in the numbers around energy, and how to compare them, I can definitely recommend a reading this chapter. The course is also available via podcast – see here for links, and covers not just energy, but terrorism, nukes, space, and global warming.

I’d be interested in hearing your comments about Muller’s information. If you have sources that you use for energy-related numbers, let me know about those too. I’m putting together a reference site for these sources, which I’ll link to on this blog as a static page when it’s ready.

The Economist magazine hosted an online debate earlier this week, on the proposition “We can solve our energy problems with existing technologies today, without the need for breakthrough innovations.”? Speaking in favor of the proposition was Joseph J. Romm, Senior Fellow at the Centre for American Progress. Speaking against was Peter Meisen, President, Global Energy Network Institute.

In my opinion, although Meisen had some good observations of some non-“business as usual” innovations that are needed, the proposition was well-defended by Romm. He argued that not only do we not have time to wait for new breakthroughs in alternative energy, we have enough technology now – solar thermal, efficiency, wind, etc. – that we can address climate change with our current capabilities. He agrees that innovations will be welcome, but they are not required.

First, new breakthrough energy technologies simply don’t enter the market fast enough to have a big impact in the time frame we care about. We need strategies that can get a 5-10% share—or more—of the global market for energy in a quarter century. Second, if you are in the kind of hurry humanity is in, then you are going to have to take unusual measures to deploy technologies far more aggressively than has ever occurred historically.

Bottom line: If we want to preserve the health and well-being of future generations, then focusing government policy and resources on speeding up existing technology deployment is far more important than focusing them on breakthrough technology development.

Meisen actually agreed completely that we need to start now with what we have today in terms of technology. But as I read it, his major point was that we need innovations not in technology, but in policy, thinking, and approach to really solve our climate and energy problems:

We now have more elegant, sophisticated and cleaner ways to generate and deliver electricity for our society. Remaining addicted to fossil fuels is damaging to our environment and bad long term policy. It is unsustainable. Aggressive policies that encourage conservation, energy efficiency, clean transport and linking renewable resources are the new priorities. Flipping our energy paradigm upside down will drive innovation and investment towards a de-carbonised future–and just makes sense..

The bottom line conclusion – get started now with the technology we have (both speakers agree) but direct some of our efforts toward new ways of solving the problem, such as improved policies from our governments (including better cooperation on international electricity transmission).

The entire debate is well worth reading on the Economist web site. They are open for comments, as am I.

If you are going to drink wine anyway, consider drinking one of Far Niente’s varietals. They’ve installed a 400kW solar PV system (PDF of SF Chronicle article) that results in a net-zero energy bill and offsets a large percentage of their CO2 emissions

When flying, which we know is one of the worst activities from a carbon standpoint, you can at least connect through Denver International, which just dedicated a 2MW solar system (PDF of Sharp Energy press release).